1. Field of the Invention
This invention relates to an apparatus for automatically mounting chip-type circuit elements on a substrate, and more particularly to an automatic mounting apparatus for automatically continuously mounting various kinds of chip-type circuit elements on a substrate for a printed circuit board.
2. Description of the Prior Art
Conventionally, various types of such an automatic mounting apparatus for chip-type circuit elements has been proposed and put in practice, which is generally constructed to continuously mount chip-type circuit elements on a single substrate while feeding several kinds of chip-type circuit elements in succession. However, in the conventional automatic mounting apparatus, when the failure in suction of a circuit element (hereinafter referred to as "suction failure") and/or the failure in suction of a circuit element in a correct position or posture (hereinafter referred to as "wrong posture") occur during the operation of sucking-up a circuit element by a mounting head, these defective circuit elements are not mounted on a substrate and only circuit elements being sucked up in correct positions or postures by the mounting heads are successively mounted on the substrate and the omitted circuit elements are properly mounted on the substrate after the mounting operations of various kinds of circuit elements are completed. This causes the mounting operation to be highly complicated and the operational efficiency to be substantially deteriorated.
In the automatic mounting apparatus of this kind, a plurality of mounting heads are required in order to successively mount various kinds of chip-type circuit elements on a substrate for a printed circuit board and that they are required to operate with satisfied reliability and at a high speed.
Also, in the automatic mounting apparatus of this kind, a tape having a plurality of chip-type circuit elements held thereon at equal intervals in a row (hereinafter referred to as "chip tape") is used so as to successively mount chip-type circuit elements on substrates. A plurality of the chip tapes having chip-type circuit elements different in kind from one another are respectively fed by a plurality of tape feeders incorporated in the automatic mounting apparatus. In the conventional automatic mounting apparatus, a plurality of the tape feeders are used each of which is generally constructed so as to intermittently rotate a tape feed drum one pitch a time with the forward movement of a base of the tape feeder horizontally slidably arranged, and peel a cover tape from the chip tape and wind up the peeled cover tape around a reel with the rearward movement of the base. Further, the mounting of circuit elements on a substrate is typically carried out in a manner such that the mounting heads moved according to a predetermined program successively take out or remove circuit elements from the chip tapes fed by the tape feeders arranged in a predetermined manner and mount the circuit elements on a substrate for a printed circuit board in order. The tape feeders which are adapted to carry out such operation are arranged along the moving passages of the respective mounting heads in a manner to be independent from one another every kind of circuit element. However, such construction of the tape feeder causes not only the maintenance and inspection of the tape feeder to require much time and labor but the replacement of a chip tape in the tape feeder to be highly troublesome due to the complication.
Still further, the conventional automatic mounting apparatus has a clamping mechanism incorporated therein which is used for carrying out the centering and turning of a circuit element. The clamping mechanism includes clamping claws pivotally supported at the intermediate portions thereof on a base of a circuit element turning device and arranged at positional intervals of 90.degree.. The claws each are provided at the one end thereof with a gear to engage the opposite gears with each other, so that the claws may be synchronously operated with the vertical movement of the circuit element turning device. However, the clamping mechanism is substantially hard to actuate one pair of the claws in synchronism with the other pair of the claws.